A new PBS documentary shines divine light on the Spanish priests and colonists who first settled the American Southwest.

The first explorers to put down roots in what would become Arizona didn’t arrive on wagon trains yelling, “Westward Ho!” Long before the earliest English-speaking, fur-trapping mountain men entered the future state in 1825, Bible-toting Spanish pioneers had migrated for centuries from another compass point.

The legacy of Catholic missions in the Southwest is part of the vast epochal tapestry depicted in Latino Americans, a six-part PBS series debuting on Tuesday, September 17 during Hispanic Heritage Month. Some of the missions in Arizona survive today – ancient, weather-worn windows into the state’s territorial past.

“American history has long been expressed from an east-west perspective,” says Adriana Bosch, the Emmy Award-winning filmmaker and executive producer of Latino Americans. “I tell the narrative in my documentary from a different direction, of people coming up from the south.”

It was a holy man – Franciscan priest Marcos de Niza – who left the earliest European footprint in Arizona. In 1539, along with a Moorish slave named Esteban de Dorantes, de Niza journeyed as far north as the Zuni pueblos and claimed to have discovered the dazzling riches of the Seven Cities of Cibola. The friar’s wildly inflated tales of wealth inspired conquistador Francisco Vázquez de Coronado’s plunder-minded expedition the following year. Like many get-rich-quick schemers, Coronado went bankrupt in the process. His greatest treasure, arguably, was stumbling upon the Grand Canyon.

Spanish missionary work in Arizona began with Franciscan priests journeying west from Santa Fe to Hopi villages in 1629. As elsewhere in the Southwest, Arizona missions were founded on a mixed mandate of religion and economics. “The missionaries were told to locate the native people living in New Spain, convert them to Catholicism, inform them they were subjects of the king, and instruct them to become good tax-paying citizens,” Anita Badertscher, Chief of Interpretation and Education at Tumacácori National Historical Park, says. “The Jesuits were responsible to teach them the ‘modern’ Spanish way of life by introducing new building and agricultural techniques.”

The earliest Franciscan missions flourished for several decades, but ultimately collapsed and were lost to the desert. More indelible were subsequent Jesuit missions, including the San Xavier del Bac and Tumacácori settlements south of present-day Tucson in the Santa Cruz Valley. In 1687, the Spanish government in Mexico City sent Jesuit priests north to bolster the colonial effort. One of them was Father Eusebio Francisco Kino. As depicted in Latino Americans, Kino was a tall Jesuit of Italian descent, and described in historical texts as energetic and charming. Native Americans largely responded to both his Catholic fervor and gifts of seeds, fruit trees, and livestock. “Nearly everywhere Kino and his companions went, [most indigenous people] welcomed them with food, arches made of branches, and simple wooden crosses,” Thomas Sheridan writes in Arizona: A History.

From 1687 until his death in 1711, Kino established more than 20 missions where Native Americans were exposed to European religion, agriculture, and language – as well as diseases such as measles and smallpox. San Xavier del Bac and Tumacácori were the farthest north in a string of remote settlements that stretched into Sonora, and their meager provisions were often raided by Apaches, who controlled the rest of what would become Arizona.

In this largely forgotten corner of the Spanish empire, the Jesuits were also in conflict with Spanish soldiers and settlers, who coveted their Native American religious converts as laborers for their mines and ranches. Economic activity eventually replaced religious conversion as the focal point of the missions’ efforts, made clear when the Spanish monarchy expelled the Jesuits in 1767 and replaced them with the more compliant Franciscans. “Spanish officials toyed with the idea of abolishing the missions but realized that missions were the cheapest and most effective way to control Christianized Indians,” Sheridan writes.

A truce with the Apaches in the 1790s allowed the missions to flourish modestly during the final years of Spanish rule, including construction of new churches at San Xavier del Bac and Tumacácori. “We have no gold, silver, iron, lead, tin, quicksilver, copper mines or marble quarries. The only public work here that is truly worthy of this report is the church at San Xavier del Bac,” noted a Spanish officer in 1804. Built under the direction of the Franciscans, the church was completed in 1797 and is considered the foremost example of Mexican Baroque architecture in the U.S.

After a decade of revolution, Mexico won its independence from Spain in 1821. The fledgling nation struggled, as the warfare had destroyed its silver-mining industry and emptied the national treasury. Funds were scarce to support the far away Santa Cruz Valley missions, which were plagued by Apache raids. Arizona’s missions soon fell on hard times. “The Tumacácori mission lost its priest in 1828 because he was born in Spain,” Badertscher says. “Mexico didn’t trust the allegiance of any native Spanish people to their new country and sent them back to Spain.” Mission San Xavier del Bac’s last Franciscan priest left in 1837. Both missions limped along, served only by the occasional visit from a circuit-riding Mexican priest.

The Mexican-American War broke out in 1846. Two years later, the Treaty of Guadalupe Hidalgo awarded the U.S. almost half of Mexico’s territory including all lands north of the Gila River. The Santa Cruz Valley’s missions remained in Mexico until the Gadsden Purchase six years later, when the U.S. acquired nearly 30,000 square miles of property for $10 million.

By 1848, the combined toll of Apache raids and meager assistance from Mexico caused the Tumacácori mission to be abandoned. “To the north, San Xavier del Bac survived because it had more resources,” Badertscher says. “The Tumacácori mission’s parish migrated to San Xavier. The people hauled with them all of the mission’s religious statues in burden baskets and wagons to San Xavier, where they were stored.”

Meanwhile, the Hispanics living in Arizona – estimated at “barely over a 1,000” by historian James Officer, even during the state’s “pre-Anglo peak” – were absorbed into the American melting pot. “Latinos became citizens by occupation,” PBS producer Bosch says – a theme explored at length in the series’ premier episode, Strangers in Their Own Land.

After becoming American territory, San Xavier del Bac came under control of the Diocese of Santa Fe in 1859. Clergy who lived in Tucson began making regular visits to conduct services at the mission, which is the oldest still-operating church in the state. Tumacácori remained abandoned, however, until President Theodore Roosevelt declared it a National Monument in 1908. The Tumacácori Museum was erected nearby in 1937 to help tell the important history of the Arizona missions.

While the Arizona missions in the Santa Cruz Valley will probably never replace Plymouth Rock in our country’s imagination, they form a unique and vital part of America’s heritage. “Many visitors aren’t quite sure what to expect when they see our brown park service sign announcing Tumacácori National Historical Park along Interstate 19,” Badertscher says. “They come away impressed with the peacefulness of the site and the overwhelming feel of the history and the lives of the people who lived at the mission.”